I decided to get started on installing the T605 in my 2002 XKR, and It's been a couple hours of fighting, but I think I am down to the last battle here.

First of all I got all of the wiring done, paired my phone, and tried making a call to the house phone. The call connects, but the radio is still playing merrily along. Tried several more times while checking, double, and triple checking my connections. Then I put a volt meter on the mute line, and it stays hovering at about 6 V, in a call or not.

So I pull that pin out of the connector, and make a call, and use a jumper wire to ground the mute line. The radio then mutes, displays "phone" and I hear the call on my end (phone ringing tone.)

Great, so why is the T605 not pulling the mute line low? After a google search I found a post from an installer who has installed several of these T605 units, and he said that a few times he had come across units that were miswired; the mute line (yellow), and phone audio - (orange) were swapped.

I ran a wire from my battery + to a voltmeter, and put the ground on the yellow wire, and made a call, it stayed between 6V and 8V. then I backed the orange wire out of the connector and connected it to the voltmeter ground, and soon as I dialed the call, it read 12V, have up, it floated back to around 8V. this means the orange wire is providing the ground for the mute!

So I swapped the yellow and orange, and now the radio switches from music to phone, and back correctly. Perhaps this is why my unit was on ebay?? Someone else couldn't get it to work maybe? anyway I wanted to share this in case someone else has trouble getting their T605 to mute the radio correctly.

This is when I ran into problem #2. I made another call to the house, and my wife answered. I could hear her saying "hello,? hello?" but she could not hear me.

I suspected that since my car was not originally equipped with the cell phone I might not have the mic. I pulled down the overhead console to look behind the screen, and it appears there are two mics there??? However I see the blue two way connector that is called out in the schematics as the factory mic connector was taped back and unused.

I plan to attach the T605 provided mic behind this screen, and splice the wiring to the blue connector, and I assume I will be in business.

But does anyone know what the other two things that look like microphones are? They both have black plastic cones on them, and seem to be aimed at the right side of the car, and are wired to a white 4 pin connector that runs to the left in the headliner...

 

I believe those are two of the four ultrasonic occupancy sensors for the passenger seat airbag. The others are on the RH A pillar and just below where the two RH side windows meet.

 

That makes sense. I had forgotten about those. I assumed Jag was using sensors in the seats like a lot of the other companies.

I wonder if the microphone will work OK squeezed behind the screen with them...

 

....and will the microphone not interfere with the passenger sensor operation.

 

On my '98 there was a provision for the microphone, facing directly rearward from the o/h console. I drilled the hole and inserted the microphone flush - there's even a yoke to hold it on the bottom of the lighting module - but found the T-605 mic wouldn't become reliable until its peripheral slots were extending into open air. Or maybe it is just highly directional, as once I extended it that far out I was able to cant it slightly toward the driver. Not a direct line-of-sight position to my mouth but closer than straight out the back window.